TBStuff TB MIDI Stuff, £1.99 (introductory price)

Compatibility: iPad (requires iOS 4.3 or later)

A new and seemingly flexible MIDI control surface app. There’s a keyboard and pad controller, plus a page editor that enables you to create custom layouts featuring sliders, knobs, X/Y pads and the like. Each control can send multiple MIDI messages simultaneously and you can have up to 32 pages open at once.

Sonosaurus ThumbJam 2, £4.99

Compatibility: iPhone, iPod touch, iPad (requires iOS 4.3 or later)

This hugely popular app, which contains great sounds that you can play in countless scales, has been given a major update. MIDI support is now comprehensive, while there are new instruments, support for stereo samples and custom scales, and enhanced import/export and copy/paste options.

Alexander Zolotov PixiTracker, £1.49

Compatibility: iPhone, iPod touch, iPad (requires iOS 3.0 or later)

A “simple and fun” iOS tracker that’s designed for quick musical sketches or chiptune tracks. You can use up to 16 sounds per song, an unlimited number of patterns and five packs’ worth of sounds. MIDI support is in place, as is audio copy/paste functionality.

VirSyn Addictive Synth 1.2, £6.99

Compatibility: iPad (requires iOS 3.2 or later)

This wavetable synth has now been kitted out with a 4-track loop recorder that allows for unlimited overdubbing. Virtual MIDI inputs and Korg’s WIST technology are now supported too, and you can export audio directly to SoundCloud. Various other tweaks have also been made.